Database Systems - Introduction to Databases and Data Warehouses. Copyright (c) 2014 Pearson Education, Inc.

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Database Systems - Introduction to Databases and Data Warehouses. Copyright (c) 2014 Pearson Education, Inc."

Transcription

1 Database Systems - Introduction to Databases and Data Warehouses Copyright (c) 2014 Pearson Education, Inc.

2 INTRODUCTION Relational database model - logical database model that represents a database as a collection of related tables Relational schema - visual depiction of the relational database model Most contemporary commercial DBMS software packages, are relational DBMS (RDBMS) software packages

3 INTRODUCTION Terminology

4 INTRODUCTION Relation - table in a relational database A table containing rows and columns The main construct in the relational database model Every relation is a table, not every table is a relation

5 INTRODUCTION Relation - table in a relational database In order for a table to be a relation the following conditions must hold: o o o o o o Each column must have a name (within one table, each column name must be unique) Within one table, each row must be unique Within each row, each value in each column must be single valued (multiple values of the content represented by the column are not allowed in any rows of the table) All values in each column must be from the same (predefined) domain Order of columns is irrelevant Order of rows is irrelevant

6 INTRODUCTION Example of relational and non-relational tables

7 INTRODUCTION Example of a relation with rows and columns appearing in a different order

8 INTRODUCTION Relational database - collection of related relations within which each relation has a unique name

9 PRIMARY KEY Primary key - column (or a set of columns) whose value is unique for each row Each relation must have a primary key The name of the primary key column is underlined in order to distinguish it from the other columns in the relation

10 PRIMARY KEY Relation with the primary key underlined

11 MAPPING ER DIAGRAMS INTO RELATIONAL SCHEMAS Once an ER diagram is constructed, it is subsequently mapped into a relational schema (collection of relations)

12 MAPPING ENTITIES Mapping entities into relations Each regular entity becomes a relation Each regular attribute of a regular entity becomes a column of the newly created relation If an entity has a single unique attribute, then that attribute becomes the primary key in the resulting mapped relation

13 MAPPING ENTITIES Entity mapped into a relation Sample data records for the mapped relation

14 MAPPING ENTITIES WITH COMPOSITE ATTRIBUTES Mapping entities with composite attributes into relations Each component of a composite attribute is mapped as a column of a relation The composite attribute itself does not appear in the mapped relation

15 MAPPING ENTITIES WITH COMPOSITE ATTRIBUTES Entity with a composite attribute mapped into a relation Sample data records for the mapped relation

16 MAPPING ENTITIES WITH COMPOSITE ATTRIBUTES The mapped relation as presented to a user in a front-end application

17 COMPOSITE PRIMARY KEY Composite primary key - a primary key that is composed of multiple columns Column names of a composite primary key are underlined, because combined together they form the primary key

18 MAPPING ENTITIES WITH UNIQUE COMPOSITE ATTRIBUTES Mapping entities with unique composite attributes into relations An entity whose only unique attribute is a composite attribute is mapped as a relation with a composite primary key

19 MAPPING ENTITIES WITH UNIQUE COMPOSITE ATTRIBUTES Entity with a unique composite attribute mapped into a relation Sample data records for the mapped relation

20 MAPPING ENTITIES WITH OPTIONAL ATTRIBUTES Mapping entities with optional attributes into relations Optional attribute of an entity is mapped as an optional column

21 MAPPING ENTITIES WITH OPTIONAL ATTRIBUTES Entity with an optional attribute mapped into a relation Sample data records for the mapped relation

22 ENTITY INTEGRITY CONSTRAINT Entity integrity constraint - in a relational table, no primary key column can have null (empty) values A rule stating that no primary key column can be optional Every RBMS enforces this rule

23 ENTITY INTEGRITY CONSTRAINT Entity integrity constraint compliance and violation example

24 ENTITY INTEGRITY CONSTRAINT Entity integrity constraint another compliance and violation example

25 FOREIGN KEY Foreign key - column in a relation that refers to a primary key column in another (referred) relation A mechanism that is used to depict relationships in the relational database model For every occurrence of a foreign key, the relational schema contains a line pointing from the foreign key to the corresponding primary key

26 MAPPING RELATIONSHIPS Mapping 1:M relationships The relation mapped from the entity on the M side of the 1:M relationship has a foreign key that corresponds to the primary key of the relation mapped from the 1 side of the 1:M relationship.

27 MAPPING RELATIONSHIPS Example - Mapping a 1:M relationship Sample data records for the mapped ER diagram

28 MAPPING RELATIONSHIPS Example - Mapping a 1:M relationship Mandatory participation on both sides Sample data records for the mapped ER diagram

29 MAPPING RELATIONSHIPS Example - Mapping a 1:M relationship Optional participation on the 1 side Sample data records for the mapped ER diagram

30 MAPPING RELATIONSHIPS Example - Mapping a 1:M relationship Optional participation on the M side Sample data records for the mapped ER diagram

31 MAPPING RELATIONSHIPS Example - Mapping a 1:M relationship Renaming a foreign key Sample data records for the mapped ER diagram

32 MAPPING RELATIONSHIPS Mapping M:N relationships In addition to the two relations representing the two entities involved in the M:N relationship, another relation is created to represent the M:N relationship itself This new relation has two foreign keys, corresponding to the primary keys of the two relations representing the two entities involved in the M:N relationship The two foreign keys form the composite primary key of the new relation

33 MAPPING RELATIONSHIPS Example - Mapping an M:N relationship Sample data records for the mapped ER diagram

34 MAPPING RELATIONSHIPS Example - Mapping an M:N relationship Optional participation on both sides Sample data records for the mapped ER diagram

35 MAPPING RELATIONSHIPS Example - Mapping a M:N relationship with an attribute Sample data records for the mapped ER diagram

36 MAPPING RELATIONSHIPS Mapping 1:1 relationships 1:1 relationships are mapped in the same way as 1:M relationships One of the resulting relations will have a foreign key pointing to the primary key of another resulting relation One of the mapped relations is chosen to have a foreign key referring to the primary key of the other mapped relation o o In cases when there is no particular advantage in choosing which resulting relation will include a foreign key, the choice can be arbitrary In other cases one choice can be more efficient than the other

37 MAPPING RELATIONSHIPS INTO RELATIONAL DATABASE CONSTRUCTS Example - Mapping a 1:1 relationship Sample data records for the mapped ER diagram

38 REFERENTIAL INTEGRITY CONSTRAINT Referential integrity constraint - In each row of a relation containing a foreign key, the value of the foreign key EITHER matches one of the values in the primary key column of the referred relation OR the value of the foreign key is null (empty). A rule that defines values that are valid for use in foreign keys In a relational schema lines pointing from the foreign key to the corresponding primary key are referred to as referential integrity constraint lines

39 REFERENTIAL INTEGRITY CONSTRAINT Referential integrity constraint compliance and violation examples

40 Example ER diagram : ZAGI Retail Company Sales Department Database

41 Example mapped relational schema: ZAGI Retail Company Sales Department Database

42 Example: Sample data records for the ZAGI Retail Company Sales Department Database

43 MAPPING CANDIDATE KEYS Mapping entities with candidate keys (multiple unique attributes) into relations One of the candidate keys is chosen by database designer the as a primary key during the mapping process Other candidate keys are mapped as non-primary key columns

44 MAPPING ENTITIES WITH CANDIDATE KEYS (MULTIPLE UNIQUE ATTRIBUTES) INTO RELATIONS Entity with candidate keys mapped into a relation Sample data records for the mapped relation

45 MAPPING CANDIDATE KEYS Entity with regular and composite candidate keys mapped into a relation Sample data records for the mapped relation

46 MAPPING MULTIVALUED ATTRIBUTES Mapping entities with multivalued attributes into relational database constructs An entity containing the multivalued attribute is mapped without the multi-valued attribute The multi-valued attribute is mapped as a separate relation that has a column representing the multivalued attribute and a foreign key column referring to the primary key of the relation resulting from the entity itself o Both of these columns form a composite primary key for the separate relation

47 MAPPING MULTIVALUED ATTRIBUTES Entity with multivalued attributes mapped into relations Sample data records for the mapped relations

48 MAPPING DERIVED ATTRIBUTES Mapping derived attributes Derived attributes are not mapped as a part of the relational schema They are implemented as a part of the database front-end application

49 MAPPING DERIVED ATTRIBUTES Entity with derived attributes mapped into a relation Sample data records for the mapped relation The relation shown as presented to a user in a front-end application

50 Example : Entity with various types of attributes mapped into a relation

51 Example : Sample data records for the mapped relations

52 MAPPING UNARY RELATIONSHIPS Mapping unary relationships Unary relationships in ER diagrams are mapped in the same way as binary relationships

53 MAPPING UNARY RELATIONSHIPS Mapping 1:M unary relationships The relation mapped from an entity involved in a 1:M unary relationship contains a foreign key that corresponds to its own primary key

54 MAPPING UNARY RELATIONSHIPS Mapping a 1:M unary relationship Sample data records for the mapped relation

55 MAPPING UNARY RELATIONSHIPS Mapping M:N unary relationships In addition to the relation representing the entity involved in a unary M:N relationship, another relation is created to represent the M:N relationship itself This new relation has two foreign keys, both of them corresponding to the primary key of the relation representing the entity involved in the unary M:N relationship Each of the foreign keys is used as a part of the composite primary key of the new relation

56 MAPPING UNARY RELATIONSHIPS Mapping a M:N unary relationship Sample data records for the mapped relations

57 MAPPING UNARY RELATIONSHIPS Mapping 1:1 unary relationships Mapped in the same way as 1:M unary relationships

58 MAPPING UNARY RELATIONSHIPS Mapping a 1:1 unary relationship Sample data records for the mapped relation

59 MAPPING MULTIPLE RELATIONSHIPS BETWEEN THE SAME ENTITIES Mapping multiple relationships between the same entities Each relationship is mapped

60 MAPPING MULTIPLE RELATIONSHIPS BETWEEN THE SAME ENTITIES Mapping multiple relationships between the same entities Sample data records for the mapped relations

61 MAPPING WEAK ENTITIES Mapping weak entities Weak entities are mapped in a same way as regular entities with one addition: o The resulting relation has a composite primary key that is composed of the partial identifier and the foreign key corresponding to the primary key of the owner entity

62 MAPPING WEAK ENTITIES Mapping a weak entity Sample data records for the mapped relations

63 MAPPING WEAK ENTITIES Mapping a weak entity with two owners Sample data records for the mapped relations

64 MAPPING WEAK ENTITIES Mapping a weak entity with no partial identifier Sample data records for the mapped relations

65 Example ER diagram : HAFH Realty Company Property Management Database

66 Example mapped relational schema: HAFH Realty Company Property Management Database

67 Example: Sample data records for the HAFH Realty Company Property Management Database (part 1)

68 Example: Sample data records for the HAFH Realty Company Property Management Database (part 2)

69 RELATIONAL DATABASE CONSTRAINTS Relational database constraints - rules that a relational database has to satisfy in order to be valid Implicit constraints o The implicit relational database model rules that a relational database must satisfy in order to be valid User-defined constraints o Database constraints that are added by the database designer

70 RELATIONAL DATABASE CONSTRAINTS Implicit constraints Each relation in a relational schema must have a different name Each relation must satisfy the following conditions: o o o o o o Each column must have a different name Each row must be unique In each row, each value in each column must be single valued Domain constraint - all values in each column must be from the same predefined domain The order of columns is irrelevant The order of rows is irrelevant Primary key constraint - each relation must have a primary key, which is a column (or a set of columns) whose value is unique for each row Entity integrity constraint Referential integrity constraint

71 RELATIONAL DATABASE CONSTRAINTS User-defined constraints Added by the database designers

72 RELATIONAL DATABASE CONSTRAINTS Specific minimum and maximum cardinalities Sample data records for the mapped relations

73 RELATIONAL DATABASE CONSTRAINTS Business rules User defined constraints that specify restrictions on databases that are not a part of the standard notation for creating ER diagrams

74 RELATIONAL DATABASE CONSTRAINTS Business rule for salary amounts Sample data records for the mapped relation

75 RELATIONAL DATABASE CONSTRAINTS Business rule for the dates of enrollment and graduation Sample data records for the mapped relation

76 RELATIONAL DATABASE CONSTRAINTS Business rule for gender of students in an organization Sample data records for the mapped relation

77 MAPPING ASSOCIATIVE ENTITIES Mapping associative entities Associative entities are mapped into relational database constructs in the identical way as M:N relationships

78 Example: An M:N relationship and associative entity mapped into a relation in the same way

79 MAPPING TERNARY RELATIONSHIPS Mapping ternary relationships Ternary relationships are used as many-to-many-to-many relationships A new relation is created with foreign keys from the participating entities forming a composite primary key of the new relation

80 Example: Mapping a ternary relationship

81 Example: Sample data records for the mapped relations

82 DESIGNER-CREATED PRIMARY KEYS AND THE AUTONUMBER OPTION Autonumber data type option - enables automatic generation of consecutive numeric data values in a column Designer-created primary key - primary key column, not called for by the original requirements, added to a table by the database designer Often used in conjunction with the autonumber data type option

83 DESIGNER-CREATED PRIMARY KEYS AND THE AUTONUMBER OPTION Entity and the resulting relation with a Entity and the resulting relation designer-created primary key column Sample data records for the relation with a designer-created primary key

84 ER AND RELATIONAL MODELING Process of requirements collection should be accompanied by the ER modeling and then followed by mapping the ER model into a subsequent relational schema Some practitioners prefer to create relational schemas straight from the requirements In such cases, the ER modeling phase is simply omitted

85 ER AND RELATIONAL MODELING Create relational schemas straight from the requirements is not advisable for following reasons ER modeling is more suited for visualization of the requirements Certain concepts can be visualized graphically only in ER diagrams Every attribute is mentioned only once in the ER diagram An ER model is a better communication and documentation device

Chapter 5: Logical Database Design and the Relational Model Part 1: Transforming EER Diagrams into Relations Modern Database Management 6 th Edition

Chapter 5: Logical Database Design and the Relational Model Part 1: Transforming EER Diagrams into Relations Modern Database Management 6 th Edition Chapter 5: Logical Database Design and the Relational Model Part 1: into Relations Modern Database Management 6 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden Robert C. Nickerson ISYS

More information

Chapter 7 Data Modeling Using the Entity- Relationship (ER) Model

Chapter 7 Data Modeling Using the Entity- Relationship (ER) Model Chapter 7 Data Modeling Using the Entity- Relationship (ER) Model Copyright 2011 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Chapter 7 Outline Using High-Level Conceptual Data Models for

More information

DATABASE DESIGN. - Developing database and information systems is performed using a development lifecycle, which consists of a series of steps.

DATABASE DESIGN. - Developing database and information systems is performed using a development lifecycle, which consists of a series of steps. DATABASE DESIGN - The ability to design databases and associated applications is critical to the success of the modern enterprise. - Database design requires understanding both the operational and business

More information

Unit 2.1. Data Analysis 1 - V2.0 1. Data Analysis 1. Dr Gordon Russell, Copyright @ Napier University

Unit 2.1. Data Analysis 1 - V2.0 1. Data Analysis 1. Dr Gordon Russell, Copyright @ Napier University Data Analysis 1 Unit 2.1 Data Analysis 1 - V2.0 1 Entity Relationship Modelling Overview Database Analysis Life Cycle Components of an Entity Relationship Diagram What is a relationship? Entities, attributes,

More information

Concepts of Database Management Seventh Edition. Chapter 6 Database Design 2: Design Method

Concepts of Database Management Seventh Edition. Chapter 6 Database Design 2: Design Method Concepts of Database Management Seventh Edition Chapter 6 Database Design 2: Design Method Objectives Discuss the general process and goals of database design Define user views and explain their function

More information

THE ENTITY- RELATIONSHIP (ER) MODEL CHAPTER 7 (6/E) CHAPTER 3 (5/E)

THE ENTITY- RELATIONSHIP (ER) MODEL CHAPTER 7 (6/E) CHAPTER 3 (5/E) THE ENTITY- RELATIONSHIP (ER) MODEL CHAPTER 7 (6/E) CHAPTER 3 (5/E) 2 LECTURE OUTLINE Using High-Level, Conceptual Data Models for Database Design Entity-Relationship (ER) model Popular high-level conceptual

More information

Data Analysis 1. SET08104 Database Systems. Copyright @ Napier University

Data Analysis 1. SET08104 Database Systems. Copyright @ Napier University Data Analysis 1 SET08104 Database Systems Copyright @ Napier University Entity Relationship Modelling Overview Database Analysis Life Cycle Components of an Entity Relationship Diagram What is a relationship?

More information

Data Modeling. Relationships within the Relational Database:

Data Modeling. Relationships within the Relational Database: Data Modeling Relationships within the Relational Database: A relationship describes association among entities. For example, a relationship exists between customers and an agent, in that an agent can

More information

Mapping an ERD to a Relational Database

Mapping an ERD to a Relational Database Mapping an ERD to a Relational Database We use E/R Modeling to understand the informational needs of a system. Once the model is satisfactory, we then implement our design in a relational database. In

More information

Modern Systems Analysis and Design

Modern Systems Analysis and Design Modern Systems Analysis and Design Prof. David Gadish Structuring System Data Requirements Learning Objectives Concisely define each of the following key data modeling terms: entity type, attribute, multivalued

More information

HNDIT 1105 Database Management Systems

HNDIT 1105 Database Management Systems HNDIT 1105 Database Management Systems Lesson 02: Database Design Process & ER Diagrams By S. Sabraz Nawaz M.Sc. In IS (SLIIT), PGD in IS (SLIIT), BBA (Hons.) Spl. in IS (SEUSL), MIEEE, MAIS Senior Lecturer

More information

1 the relational data model The relational model of data was introduced by E.F. Codd (1970). 1.1 relational model concepts The relational model repres

1 the relational data model The relational model of data was introduced by E.F. Codd (1970). 1.1 relational model concepts The relational model repres database systems formal definitions of the relational data model [03] s. yurttaοs 1 1 the relational data model The relational model of data was introduced by E.F. Codd (1970). 1.1 relational model concepts

More information

Concepts of Database Management, Fifth Edition. Chapter 6: Database Design 2: Design Methodology

Concepts of Database Management, Fifth Edition. Chapter 6: Database Design 2: Design Methodology Concepts of Database Management, Fifth Edition Chapter 6: Database Design 2: Design Methodology Objectives Discuss the general process and goals of database design Define user views and explain their function

More information

Systems Analysis and Design

Systems Analysis and Design Systems Analysis and Design Slides adapted from Jeffrey A. Hoffer, University of Dayton Joey F. George, Florida State University Joseph S. Valacich, Washington State University Modern Systems Analysis

More information

COMP 378 Database Systems Notes for Chapter 7 of Database System Concepts Database Design and the Entity-Relationship Model

COMP 378 Database Systems Notes for Chapter 7 of Database System Concepts Database Design and the Entity-Relationship Model COMP 378 Database Systems Notes for Chapter 7 of Database System Concepts Database Design and the Entity-Relationship Model The entity-relationship (E-R) model is a a data model in which information stored

More information

RELATIONSHIP STRENGTH

RELATIONSHIP STRENGTH Connectivity and Cardinality The term connectivity is used to describe the relationship classification. Cardinality expresses the minimum and maximum number of entity occurrences associated with one occurrence

More information

D.Hemavathi,R.Venkatalakshmi Assistant Professor, SRM University, Kattankulathur

D.Hemavathi,R.Venkatalakshmi Assistant Professor, SRM University, Kattankulathur DATABASE SYSTEMS IT 0303 5 TH Semester D.Hemavathi,R.Venkatalakshmi Assistant Professor, SRM University, Kattankulathur School of Computing, Department of IT Unit 2:Entity Relationship Model Disclaimer

More information

Database Design and the Entity-Relationship Model

Database Design and the Entity-Relationship Model Database Design and the Entity-Relationship Model Computer Science 460/660 Boston University Fall 2013 David G. Sullivan, Ph.D. Database Design In database design, we determine: which data fields to include

More information

ETEC 2601 Database Systems

ETEC 2601 Database Systems ETEC 2601 Database Systems Chapter 5: Data Modeling With The Entity-Relationship Model Copyright 2004-2010 J. B. Gallaher The Data Model The design of a database Is the way the user conceives the information

More information

CSC 742 Database Management Systems

CSC 742 Database Management Systems CSC 742 Database Management Systems Topic #4: Data Modeling Spring 2002 CSC 742: DBMS by Dr. Peng Ning 1 Phases of Database Design Requirement Collection/Analysis Functional Requirements Functional Analysis

More information

Entity-Relationship Model. Modeling. Entity-Relationship Model. How do we design the database for an application?

Entity-Relationship Model. Modeling. Entity-Relationship Model. How do we design the database for an application? How do we design the database for an application? Entity-Relationship Model Dr. McNamara CSCI 371 Databases Fall 2006 1. Conceptual Design: Analyze the problem. Identify the entities, relationships, and

More information

Chapter 2: Entity-Relationship Model. Entity Sets. " Example: specific person, company, event, plant

Chapter 2: Entity-Relationship Model. Entity Sets.  Example: specific person, company, event, plant Chapter 2: Entity-Relationship Model! Entity Sets! Relationship Sets! Design Issues! Mapping Constraints! Keys! E-R Diagram! Extended E-R Features! Design of an E-R Database Schema! Reduction of an E-R

More information

Database Design. Marta Jakubowska-Sobczak IT/ADC based on slides prepared by Paula Figueiredo, IT/DB

Database Design. Marta Jakubowska-Sobczak IT/ADC based on slides prepared by Paula Figueiredo, IT/DB Marta Jakubowska-Sobczak IT/ADC based on slides prepared by Paula Figueiredo, IT/DB Outline Database concepts Conceptual Design Logical Design Communicating with the RDBMS 2 Some concepts Database: an

More information

Fundamentals of Database Design

Fundamentals of Database Design Fundamentals of Database Design Zornitsa Zaharieva CERN Data Management Section - Controls Group Accelerators and Beams Department /AB-CO-DM/ 23-FEB-2005 Contents : Introduction to Databases : Main Database

More information

Constraints in ER Models. Types of Constraints. Keys. CS 317, Fall 2007

Constraints in ER Models. Types of Constraints. Keys. CS 317, Fall 2007 Constraints in ER Models CS 317, Fall 2007 Types of Constraints Keys are attributes or sets of attributes that uniquely identify an entity within its entity set. Single-value constraints require that a

More information

Database Design Methodology

Database Design Methodology Topic 7 Database Design Methodology LEARNING OUTCOMES When you have completed this Topic you should be able to: 1. Discuss the purpose of a design methodology. 2. Explain three main phases of design methodology.

More information

Entity-Relationship Model

Entity-Relationship Model UNIT -2 Entity-Relationship Model Introduction to ER Model ER model is represents real world situations using concepts, which are commonly used by people. It allows defining a representation of the real

More information

Basic Database Concepts

Basic Database Concepts Tore Risch Uppsala University, Sweden UDBL Basic Database Concepts What is a database? A database is a collection of related data stored in a computer managed by a DBMS. What is a DBMS, Database Management

More information

Chapter 2: Entity-Relationship Model. E-R R Diagrams

Chapter 2: Entity-Relationship Model. E-R R Diagrams Chapter 2: Entity-Relationship Model What s the use of the E-R model? Entity Sets Relationship Sets Design Issues Mapping Constraints Keys E-R Diagram Extended E-R Features Design of an E-R Database Schema

More information

Chapter 3. Data Modeling Using the Entity-Relationship (ER) Model

Chapter 3. Data Modeling Using the Entity-Relationship (ER) Model Chapter 3 Data Modeling Using the Entity-Relationship (ER) Model Chapter Outline Overview of Database Design Process Example Database Application (COMPANY) ER Model Concepts Entities and Attributes Entity

More information

DATABASE MANAGEMENT SYSTEMS. Question Bank:

DATABASE MANAGEMENT SYSTEMS. Question Bank: DATABASE MANAGEMENT SYSTEMS Question Bank: UNIT 1 1. Define Database? 2. What is a DBMS? 3. What is the need for database systems? 4. Define tupule? 5. What are the responsibilities of DBA? 6. Define schema?

More information

Entity-Relationship Model. Database Modeling (Part 1) Entity. Entity-Relationship Model EMPLOYEE

Entity-Relationship Model. Database Modeling (Part 1) Entity. Entity-Relationship Model EMPLOYEE Entity-Relationship Model Database Modeling (Part 1) A conceptual data model, which is a representation of the structure of a database that is independent of the software that will be used to implement

More information

www.gr8ambitionz.com

www.gr8ambitionz.com Data Base Management Systems (DBMS) Study Material (Objective Type questions with Answers) Shared by Akhil Arora Powered by www. your A to Z competitive exam guide Database Objective type questions Q.1

More information

XV. The Entity-Relationship Model

XV. The Entity-Relationship Model XV. The Entity-Relationship Model The Entity-Relationship Model Entities, Relationships and Attributes Cardinalities, Identifiers and Generalization Documentation of E-R Diagrams and Business Rules The

More information

Lecture 12: Entity Relationship Modelling

Lecture 12: Entity Relationship Modelling Lecture 12: Entity Relationship Modelling The Entity-Relationship Model Entities Relationships Attributes Constraining the instances Cardinalities Identifiers Generalization 2004-5 Steve Easterbrook. This

More information

We know how to query a database using SQL. A set of tables and their schemas are given Data are properly loaded

We know how to query a database using SQL. A set of tables and their schemas are given Data are properly loaded E-R Diagram Database Development We know how to query a database using SQL A set of tables and their schemas are given Data are properly loaded But, how can we develop appropriate tables and their schema

More information

A. TRUE-FALSE: GROUP 2 PRACTICE EXAMPLES FOR THE REVIEW QUIZ:

A. TRUE-FALSE: GROUP 2 PRACTICE EXAMPLES FOR THE REVIEW QUIZ: GROUP 2 PRACTICE EXAMPLES FOR THE REVIEW QUIZ: Review Quiz will contain very similar question as below. Some questions may even be repeated. The order of the questions are random and are not in order of

More information

Fundamentals of Database System

Fundamentals of Database System Fundamentals of Database System Chapter 4 Normalization Fundamentals of Database Systems (Chapter 4) Page 1 Introduction To Normalization In general, the goal of a relational database design is to generate

More information

Bridge from Entity Relationship modeling to creating SQL databases, tables, & relations

Bridge from Entity Relationship modeling to creating SQL databases, tables, & relations 1 Topics for this week: 1. Good Design 2. Functional Dependencies 3. Normalization Readings for this week: 1. E&N, Ch. 10.1-10.6; 12.2 2. Quickstart, Ch. 3 3. Complete the tutorial at http://sqlcourse2.com/

More information

7.1 The Information system

7.1 The Information system Chapter 7. Database Planning, Design and Administration Last few decades have seen proliferation of software applications, many requiring constant maintenance involving: correcting faults, implementing

More information

Databases and BigData

Databases and BigData Eduardo Cunha de Almeida eduardo.almeida@uni.lu Outline of the course Introduction Database Systems (E. Almeida) Distributed Hash Tables and P2P (C. Cassagnes) NewSQL (D. Kim and J. Meira) NoSQL (D. Kim)

More information

Chapter 2: Entity-Relationship Model

Chapter 2: Entity-Relationship Model Chapter 2: Entity-Relationship Model Entity Sets Relationship Sets Design Issues Mapping Constraints Keys E R Diagram Extended E-R Features Design of an E-R Database Schema Reduction of an E-R Schema to

More information

IT2305 Database Systems I (Compulsory)

IT2305 Database Systems I (Compulsory) Database Systems I (Compulsory) INTRODUCTION This is one of the 4 modules designed for Semester 2 of Bachelor of Information Technology Degree program. CREDITS: 04 LEARNING OUTCOMES On completion of this

More information

Mapping Data Models to a Relational Database

Mapping Data Models to a Relational Database Mapping Data Models to a Relational Database Time to dovetail two prior topics: data modeling (E-R, UML) and the relational data model (structure, algebra) To recap, this is how they relate: The data model

More information

Database Design Overview. Conceptual Design ER Model. Entities and Entity Sets. Entity Set Representation. Keys

Database Design Overview. Conceptual Design ER Model. Entities and Entity Sets. Entity Set Representation. Keys Database Design Overview Conceptual Design. The Entity-Relationship (ER) Model CS430/630 Lecture 12 Conceptual design The Entity-Relationship (ER) Model, UML High-level, close to human thinking Semantic

More information

The Relational Model. Why Study the Relational Model? Relational Database: Definitions

The Relational Model. Why Study the Relational Model? Relational Database: Definitions The Relational Model Database Management Systems, R. Ramakrishnan and J. Gehrke 1 Why Study the Relational Model? Most widely used model. Vendors: IBM, Microsoft, Oracle, Sybase, etc. Legacy systems in

More information

LiTH, Tekniska högskolan vid Linköpings universitet 1(7) IDA, Institutionen för datavetenskap Juha Takkinen 2007-05-24

LiTH, Tekniska högskolan vid Linköpings universitet 1(7) IDA, Institutionen för datavetenskap Juha Takkinen 2007-05-24 LiTH, Tekniska högskolan vid Linköpings universitet 1(7) IDA, Institutionen för datavetenskap Juha Takkinen 2007-05-24 1. A database schema is a. the state of the db b. a description of the db using a

More information

There are five fields or columns, with names and types as shown above.

There are five fields or columns, with names and types as shown above. 3 THE RELATIONAL MODEL Exercise 3.1 Define the following terms: relation schema, relational database schema, domain, attribute, attribute domain, relation instance, relation cardinality, andrelation degree.

More information

DATABASE SYSTEMS. Chapter 7 Normalisation

DATABASE SYSTEMS. Chapter 7 Normalisation DATABASE SYSTEMS DESIGN IMPLEMENTATION AND MANAGEMENT INTERNATIONAL EDITION ROB CORONEL CROCKETT Chapter 7 Normalisation 1 (Rob, Coronel & Crockett 978184480731) In this chapter, you will learn: What normalization

More information

CSCD43: Database Systems Technology. Lecture 2

CSCD43: Database Systems Technology. Lecture 2 Lecture 2 Wael Aboulsaadat Acknowledgment: these slides are based on Prof. Garcia-Molina & Prof. Ullman slides accompanying the course s textbook. Steps in Database Design Conceptual Design Logical Design

More information

Introduction. Database Management Systems

Introduction. Database Management Systems Introduction Database Management Systems Database Management System (DBMS) Collection of interrelated data and set of programs to access the data Convenient and efficient processing of data Database Application

More information

CS2Bh: Current Technologies. Introduction to XML and Relational Databases. The Relational Model. The relational model

CS2Bh: Current Technologies. Introduction to XML and Relational Databases. The Relational Model. The relational model CS2Bh: Current Technologies Introduction to XML and Relational Databases Spring 2005 The Relational Model CS2 Spring 2005 (LN6) 1 The relational model Proposed by Codd in 1970. It is the dominant data

More information

The Relational Model. Why Study the Relational Model? Relational Database: Definitions. Chapter 3

The Relational Model. Why Study the Relational Model? Relational Database: Definitions. Chapter 3 The Relational Model Chapter 3 Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Why Study the Relational Model? Most widely used model. Vendors: IBM, Informix, Microsoft, Oracle, Sybase,

More information

Component 4: Introduction to Information and Computer Science

Component 4: Introduction to Information and Computer Science Component 4: Introduction to Information and Computer Science Unit 6: Databases and SQL Lecture 2 This material was developed by Oregon Health & Science University, funded by the Department of Health and

More information

Lesson 8: Introduction to Databases E-R Data Modeling

Lesson 8: Introduction to Databases E-R Data Modeling Lesson 8: Introduction to Databases E-R Data Modeling Contents Introduction to Databases Abstraction, Schemas, and Views Data Models Database Management System (DBMS) Components Entity Relationship Data

More information

Section of DBMS Selection & Evaluation Questionnaire

Section of DBMS Selection & Evaluation Questionnaire Section of DBMS Selection & Evaluation Questionnaire Whitemarsh Information Systems Corporation 2008 Althea Lane Bowie, Maryland 20716 Tele: 301-249-1142 Email: mmgorman@wiscorp.com Web: www.wiscorp.com

More information

Database Design Process

Database Design Process Database Design Process Entity-Relationship Model From Chapter 5, Kroenke book Requirements analysis Conceptual design data model Logical design Schema refinement: Normalization Physical tuning Problem:

More information

ETL Process in Data Warehouse. G.Lakshmi Priya & Razia Sultana.A Assistant Professor/IT

ETL Process in Data Warehouse. G.Lakshmi Priya & Razia Sultana.A Assistant Professor/IT ETL Process in Data Warehouse G.Lakshmi Priya & Razia Sultana.A Assistant Professor/IT Outline ETL Extraction Transformation Loading ETL Overview Extraction Transformation Loading ETL To get data out of

More information

Database Design Process

Database Design Process Entity-Relationship Model Chapter 3, Part 1 Database Design Process Requirements analysis Conceptual design data model Logical design Schema refinement: Normalization Physical tuning 1 Problem: University

More information

Data Modeling. Database Systems: The Complete Book Ch. 4.1-4.5, 7.1-7.4

Data Modeling. Database Systems: The Complete Book Ch. 4.1-4.5, 7.1-7.4 Data Modeling Database Systems: The Complete Book Ch. 4.1-4.5, 7.1-7.4 Data Modeling Schema: The structure of the data Structured Data: Relational, XML-DTD, etc Unstructured Data: CSV, JSON But where does

More information

Database Design. Adrienne Watt. Port Moody

Database Design. Adrienne Watt. Port Moody Database Design Database Design Adrienne Watt Port Moody Except for third party materials and otherwise stated, content on this site is made available under a Creative Commons Attribution 2.5 Canada License.

More information

IT2304: Database Systems 1 (DBS 1)

IT2304: Database Systems 1 (DBS 1) : Database Systems 1 (DBS 1) (Compulsory) 1. OUTLINE OF SYLLABUS Topic Minimum number of hours Introduction to DBMS 07 Relational Data Model 03 Data manipulation using Relational Algebra 06 Data manipulation

More information

Data Modeling: Part 1. Entity Relationship (ER) Model

Data Modeling: Part 1. Entity Relationship (ER) Model Data Modeling: Part 1 Entity Relationship (ER) Model MBA 8473 1 Cognitive Objectives (Module 2) 32. Explain the three-step process of data-driven information system (IS) development 33. Examine the purpose

More information

Database Design Process. Databases - Entity-Relationship Modelling. Requirements Analysis. Database Design

Database Design Process. Databases - Entity-Relationship Modelling. Requirements Analysis. Database Design Process Databases - Entity-Relationship Modelling Ramakrishnan & Gehrke identify six main steps in designing a database Requirements Analysis Conceptual Design Logical Design Schema Refinement Physical

More information

A brief overview of developing a conceptual data model as the first step in creating a relational database.

A brief overview of developing a conceptual data model as the first step in creating a relational database. Data Modeling Windows Enterprise Support Database Services provides the following documentation about relational database design, the relational database model, and relational database software. Introduction

More information

The Entity-Relationship Model

The Entity-Relationship Model The Entity-Relationship Model 221 After completing this chapter, you should be able to explain the three phases of database design, Why are multiple phases useful? evaluate the significance of the Entity-Relationship

More information

Lecture 6. SQL, Logical DB Design

Lecture 6. SQL, Logical DB Design Lecture 6 SQL, Logical DB Design Relational Query Languages A major strength of the relational model: supports simple, powerful querying of data. Queries can be written intuitively, and the DBMS is responsible

More information

Relational model. Relational model - practice. Relational Database Definitions 9/27/11. Relational model. Relational Database: Terminology

Relational model. Relational model - practice. Relational Database Definitions 9/27/11. Relational model. Relational Database: Terminology COS 597A: Principles of Database and Information Systems elational model elational model A formal (mathematical) model to represent objects (data/information), relationships between objects Constraints

More information

2. Basic Relational Data Model

2. Basic Relational Data Model 2. Basic Relational Data Model 2.1 Introduction Basic concepts of information models, their realisation in databases comprising data objects and object relationships, and their management by DBMS s that

More information

not necessarily strictly sequential feedback loops exist, i.e. may need to revisit earlier stages during a later stage

not necessarily strictly sequential feedback loops exist, i.e. may need to revisit earlier stages during a later stage Database Design Process there are six stages in the design of a database: 1. requirement analysis 2. conceptual database design 3. choice of the DBMS 4. data model mapping 5. physical design 6. implementation

More information

Web Contents for Database Design Book

Web Contents for Database Design Book Web Contents for Database Design Book Link to the Authors Web Site The Perpetual Technologies web site, http://www.perptech.com, contains information about relational database technology, with specialization

More information

DATABASE NORMALIZATION

DATABASE NORMALIZATION DATABASE NORMALIZATION Normalization: process of efficiently organizing data in the DB. RELATIONS (attributes grouped together) Accurate representation of data, relationships and constraints. Goal: - Eliminate

More information

Databasesystemer, forår 2005 IT Universitetet i København. Forelæsning 3: Business rules, constraints & triggers. 3. marts 2005

Databasesystemer, forår 2005 IT Universitetet i København. Forelæsning 3: Business rules, constraints & triggers. 3. marts 2005 Databasesystemer, forår 2005 IT Universitetet i København Forelæsning 3: Business rules, constraints & triggers. 3. marts 2005 Forelæser: Rasmus Pagh Today s lecture Constraints and triggers Uniqueness

More information

Outline. Data Modeling. Conceptual Design. ER Model Basics: Entities. ER Model Basics: Relationships. Ternary Relationships. Yanlei Diao UMass Amherst

Outline. Data Modeling. Conceptual Design. ER Model Basics: Entities. ER Model Basics: Relationships. Ternary Relationships. Yanlei Diao UMass Amherst Outline Data Modeling Yanlei Diao UMass Amherst v Conceptual Design: ER Model v Relational Model v Logical Design: from ER to Relational Slides Courtesy of R. Ramakrishnan and J. Gehrke 1 2 Conceptual

More information

Review: Participation Constraints

Review: Participation Constraints Review: Participation Constraints Does every department have a manager? If so, this is a participation constraint: the participation of Departments in Manages is said to be total (vs. partial). Every did

More information

2. Conceptual Modeling using the Entity-Relationship Model

2. Conceptual Modeling using the Entity-Relationship Model ECS-165A WQ 11 15 Contents 2. Conceptual Modeling using the Entity-Relationship Model Basic concepts: entities and entity types, attributes and keys, relationships and relationship types Entity-Relationship

More information

Entity-Relationship (ER) Model

Entity-Relationship (ER) Model ER Design (1) Entity-Relationship (ER) Model Elements in a database: data entries Data entries represent Entities: data objects, e.g., students, courses, and instructors Relationships among entities: students

More information

Data Modeling Basics

Data Modeling Basics Information Technology Standard Commonwealth of Pennsylvania Governor's Office of Administration/Office for Information Technology STD Number: STD-INF003B STD Title: Data Modeling Basics Issued by: Deputy

More information

Title: ENHANCEMENT OF ERD. Research by: Student Name : Wafa Ali Edrees. Student Id : 201130061. Collage Of Computer Science and Information System

Title: ENHANCEMENT OF ERD. Research by: Student Name : Wafa Ali Edrees. Student Id : 201130061. Collage Of Computer Science and Information System Title: ENHANCEMENT OF ERD Research by: Student Name : Wafa Ali Edrees Student Id : 201130061 Collage Of Computer Science and Information System Level : 5 Teacher : Arshia Arjumand Banu 1 ENHANCEMENT OF

More information

Foundations of Information Management

Foundations of Information Management Foundations of Information Management - WS 2012/13 - Juniorprofessor Alexander Markowetz Bonn Aachen International Center for Information Technology (B-IT) Data & Databases Data: Simple information Database:

More information

Database Management Systems

Database Management Systems Database Management Systems Database Design (1) 1 Topics Information Systems Life Cycle Data Base Design Logical Design Physical Design Entity Relationship (ER) Model Entity Relationship Attributes Cardinality

More information

SQL DDL. Applied Databases. Inclusion Constraints. Key Constraints

SQL DDL. Applied Databases. Inclusion Constraints. Key Constraints Applied Databases Handout 2. Database Design. 5 October 2010 SQL DDL In its simplest use, SQL s Data Definition Language (DDL) provides a name and a type for each column of a table. CREATE TABLE Hikers

More information

Exercise 1: Relational Model

Exercise 1: Relational Model Exercise 1: Relational Model 1. Consider the relational database of next relational schema with 3 relations. What are the best possible primary keys in each relation? employ(person_name, street, city)

More information

Relational Databases

Relational Databases Relational Databases Jan Chomicki University at Buffalo Jan Chomicki () Relational databases 1 / 18 Relational data model Domain domain: predefined set of atomic values: integers, strings,... every attribute

More information

The Relational Model. Ramakrishnan&Gehrke, Chapter 3 CS4320 1

The Relational Model. Ramakrishnan&Gehrke, Chapter 3 CS4320 1 The Relational Model Ramakrishnan&Gehrke, Chapter 3 CS4320 1 Why Study the Relational Model? Most widely used model. Vendors: IBM, Informix, Microsoft, Oracle, Sybase, etc. Legacy systems in older models

More information

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd.

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd. The Entity- Relationship Model R &G - Chapter 2 A relationship, I think, is like a shark, you know? It has to constantly move forward or it dies. And I think what we got on our hands is a dead shark. Woody

More information

Database Design Methodology

Database Design Methodology Database Design Methodology Three phases Database Design Methodology Logical database Physical database Constructing a model of the information used in an enterprise on a specific data model but independent

More information

DATABASE SCHEMA DESIGN ENTITY-RELATIONSHIP MODEL. CS121: Introduction to Relational Database Systems Fall 2015 Lecture 14

DATABASE SCHEMA DESIGN ENTITY-RELATIONSHIP MODEL. CS121: Introduction to Relational Database Systems Fall 2015 Lecture 14 DATABASE SCHEMA DESIGN ENTITY-RELATIONSHIP MODEL CS121: Introduction to Relational Database Systems Fall 2015 Lecture 14 Designing Database Applications 2 Database applications are large and complex A

More information

SQL Boot Camp. End To End SQL Query Writing, Database Design & Development Training. SQL Boot Camp Training.

SQL Boot Camp. End To End SQL Query Writing, Database Design & Development Training. SQL Boot Camp Training. Page 1 of 7 SQL Boot Camp www.sqlbootcamp.com End To End SQL Query Writing, Database Design & Development Training Database Design Query Optimization SQL Boot Camp Training Database Development SQL Query

More information

The Entity-Relationship (ER) Model

The Entity-Relationship (ER) Model The Entity-Relationship (ER) Model (Study Cow book Chapter 2) Comp 521 Files and Databases Spring 2010 1 Overview of Database Design Conceptual design: (ER Model is used at this stage.) What are the entities

More information

BCA. Database Management System

BCA. Database Management System BCA IV Sem Database Management System Multiple choice questions 1. A Database Management System (DBMS) is A. Collection of interrelated data B. Collection of programs to access data C. Collection of data

More information

The Entity-Relationship Model

The Entity-Relationship Model The Entity-Relationship Model Chapter 2 Instructor: Vladimir Zadorozhny vladimir@sis.pitt.edu Information Science Program School of Information Sciences, University of Pittsburgh 1 Database: a Set of Relations

More information

Reducing ER Schema to Relational Schema

Reducing ER Schema to Relational Schema Reducing ER Schema to Relational Schema Excerpt from Chapter 3, Database Management Systems 3ed, R. Ramakrishnan and J. Gehrke 1 Logical DB Design: ER to Relational Entity sets to tables: ssn name Employees

More information

three Entity-Relationship Modeling chapter OVERVIEW CHAPTER

three Entity-Relationship Modeling chapter OVERVIEW CHAPTER three Entity-Relationship Modeling CHAPTER chapter OVERVIEW 3.1 Introduction 3.2 The Entity-Relationship Model 3.3 Entity 3.4 Attributes 3.5 Relationships 3.6 Degree of a Relationship 3.7 Cardinality of

More information

Database Design. Database Design I: The Entity-Relationship Model. Entity Type (con t) Chapter 4. Entity: an object that is involved in the enterprise

Database Design. Database Design I: The Entity-Relationship Model. Entity Type (con t) Chapter 4. Entity: an object that is involved in the enterprise Database Design Database Design I: The Entity-Relationship Model Chapter 4 Goal: specification of database schema Methodology: Use E-R R model to get a high-level graphical view of essential components

More information

ER modelling, Weak Entities, Class Hierarchies, Aggregation

ER modelling, Weak Entities, Class Hierarchies, Aggregation CS344 Database Management Systems ER modelling, Weak Entities, Class Hierarchies, Aggregation Aug 2 nd - Lecture Notes (Summary) Submitted by - N. Vishnu Teja Saurabh Saxena 09010125 09010145 (Most the

More information

Designing a Database Schema

Designing a Database Schema Week 10: Database Design Database Design From an ER Schema to a Relational One Restructuring an ER schema Performance Analysis Analysis of Redundancies, Removing Generalizations Translation into a Relational

More information

AVOIDANCE OF CYCLICAL REFERENCE OF FOREIGN KEYS IN DATA MODELING USING THE ENTITY-RELATIONSHIP MODEL

AVOIDANCE OF CYCLICAL REFERENCE OF FOREIGN KEYS IN DATA MODELING USING THE ENTITY-RELATIONSHIP MODEL AVOIDANCE OF CYCLICAL REFERENCE OF FOREIGN KEYS IN DATA MODELING USING THE ENTITY-RELATIONSHIP MODEL Ben B. Kim, Seattle University, bkim@seattleu.edu ABSTRACT The entity-relationship (ER model is clearly

More information

ENTITY-RELATIONSHIP (ER) MODEL. 1. Background (Five Levels of Relational Database Design)

ENTITY-RELATIONSHIP (ER) MODEL. 1. Background (Five Levels of Relational Database Design) Lecture Note #2 COSC4820/5820 Database Systems Department of Computer Science University of Wyoming Byunggu Yu, 01/21/2002 ENTITY-RELATIONSHIP (ER) MODEL (Originally designed by Peter Chen, 1976) 1. Background

More information

Database Design and the ER model

Database Design and the ER model Database Design and the ER model 1. Database design Database design: Description of the data environment An abstraction, driven by anticipated applications Database model: A formalism for specifying database

More information